Karen, at points, will appear to know things about you that she shouldn’t.
Photograph: Blast Theory

If a life coach in an app asks you:

Sex with a stranger is more exciting, right?

What would you answer? This was one of our starting points for new smartphone app, Karen. As with my fellow Blast Theory artists Ju Row Farr and Nick Tandavanitj, who helped create the app, I’m fascinated by the new kinds of intimacy, interaction and artistic experience created by mobile phones.

I’ve always been a sucker for those quizzes in glossy mags that promise something salacious with a side order of self knowledge (“Test your sex IQ”). While they rarely deliver on either front, these quizzes have endured for decades. Now websites such as BuzzFeed carry on the tradition of feeding our desire for personal know-how in bite-size chunks.

When John McGrath, National Theatre Wales’s artistic director, first asked us to develop a project with the organisation in 2013, we were keen to create a personal and intimate experience for smartphones in which you interact directly with the lead character. We wanted you to be challenged about how honest and open you might be and to experience the thrill of having your personality appraised.

We became fascinated with big data, in particular how governments and large companies are collecting information about us secretly and using it without our consent.

First steps for us included meeting with Dr Kelly Page, an expert in this area, to learn about the techniques developed by psychologists to measure personalities, and research into the history of the subject. We then rifled through hundreds of personality tests from across the decades. We chose some of the most fascinating, unnerving or significant scales and wove them into the story of Karen, a divorcee with just enough knowledge to be dangerous.

You interact with Karen through the app. At the start, she asks you some questions about your outlook and views of the world, to get a better understanding of you. She, and the app’s software, profiles you. Karen will give you advice based on your answers and over the next week you will have calls with her once or twice a day. I won’t spoil the experience, but it soon becomes clear that Karen is somewhat chaotic, with little care for personal/professional boundaries. She will get more and more curious and at points, will seem to know things about you that she shouldn’t. Is she spying on you?

That last point is important. Privacy and our use of user data was, of course, a key concern. The app has to gather and make use of highly personal information and we required the trust of users to do that. We spent a lot of time creating a privacy policy that was clear and robust.

We also had grand plans for how geolocation might be used. We wanted to ask the user whether they were at home, at work or out and about. Then we planned to give them different sessions based on where they were, but it proved just too complex. We were already in unknown territory and the last three months of development were a “bonfire of the features” at times! We stripped it down further and further.

Perhaps the biggest challenge we’ve faced is that the app is a hybrid, sitting somewhere between a game, a drama and a self-help quiz. We developed a strong story for Karen’s world with a great deal happening, but then realised this excluded the participant/player from what was happening.

Tester feedback became more positive as we stripped the story back to make it a world that exists almost entirely between the user and Karen. Words such as “intimate” and “addictive” started to crop up in tester reports and we knew we were on the right track.

The Android version of the app will launch on 21 August, then in September, for one night only, we’ll invite everyone who completed the app to meet Karen in person at a secret UK location.

Our goal for the app was 3,000 downloads and this week we passed 10,000 for iOS. Most encouragingly, 35% of those who download the app go on to complete the nine-day long experience. Of those who finish, 37% have bought the personalised data report that we offer for £2.99. It shows that there’s an appetite for artistic experiences on mobile and that users are willing to commit time to and spend money on them.

App facts

Length of the project: three years; final shoot and build, six monthsCompanies involved: Blast Theory, National Theatre Wales, The Space, University of NottinghamSize of the team: three artists, one lead researcher, one assistant, one lead developer, one producer, two actors, one director of photography, one sound person, one editor, an army of volunteers and 539 Kickstarter backers